There is known a projection type display apparatus that projects an image on a screen. In most of such projection type display apparatuses, a liquid crystal panel (liquid crystal light shutter) is used for forming the image.
Such a liquid crystal panel has a configuration in which, for example, an opposed substrate for a liquid crystal panel that is provided with a black matrix, a common electrode and the like is joined to a liquid crystal driving substrate provided with a large number of thin film transistors (TFT) for controlling respective pixels and a large number of pixel electrodes via a liquid crystal layer.
In the liquid crystal panel (TFT liquid crystal panel) having such a configuration, since the black matrix is formed in a portion other than the portions to become the pixels in the opposed substrate for a liquid crystal panel, a region for light transmitting the liquid crystal panel is restricted. This makes light transmittance be lowered.
In order to improve the light transmittance for the liquid crystal panel, there is known a liquid crystal panel in which a large number of minute microlenses are provided at the positions corresponding to the respective pixels in the opposed substrate for a liquid crystal panel. According to such a liquid crystal panel, light transmitting an opposed substrate for a liquid crystal panel is condensed into openings formed in a black matrix, and this makes it possible to improve light transmittance.
As a method of forming such microlenses, for example, a method in which an uncured photocuring resin material is supplied on a substrate with concave portions on one major surface of which a plurality of concave portions for forming microlenses are formed, a flat transparent substrate (cover glass) is joined to the supplied resin material to press and bring into contact with the supplied resin material, and the supplied resin material is then cured, that is, a so-called 2P method is known (for example, see JP-A-2001-92365).
However, in the conventional techniques, steps such as alignment of the cover glass, polish of the cover glass in order to obtain the optimal optical path length are required, and therefore, the manufacturing process of a microlens substrate has been complicated. Further, in the case where the cover glass is polished, there was fear that stains and the like occur due to the polish process. As a result, an appropriate cleaning process is required, and therefore, there is a problem that the manufacturing process has been further complicated and the manufacturing costs are made to be heightened. The complication of the manufacturing process makes a factor of debasement of the microlens substrate, and therefore, there was a possibility that lowering of the yield ratio is generated. In particular, in the 2P method, since a microlens substrate is manufactured using three members including a resin layer formed of a photocuring resin material, a cover glass, and a substrate with concave portions, strain or the like tends to be generated due to difference in coefficients of thermal expansion thereof, and as a result, there is a possibility that characteristics of the microlens substrate such as an optical characteristic are lowered.